Abstract

PURPOSE To look for changes in the motor cortex in patients with brain tumors.

METHODS Both cerebral hemispheres in seven patients with brain tumors were examined with functional MR imaging during a motor task performed by the hand opposite the site of tumor. The ratio of the activated area in the motor cortex ipsilateral/contralateral to the tested hand was calculated for each subject. Twenty healthy subjects were also examined in the same manner for comparison.

RESULTS The ratio of the ipsilateral/contralateral activated area was abnormally high in three patients with tumor-related paresis of the tested hand. The ratio was significantly greater in patients with paresis than in healthy subjects.

CONCLUSION This study demonstrated increased activity in the ipsilateral (unaffected) motor area during a hand motor task in patients with brain tumor and paresis, which was thought to reflect compensatory reorganization induced by the functional damage.